package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.hmdp.dto.Result;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.Duration;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * <p>
 * 服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private ISeckillVoucherService seckillVoucherService;
    @Resource
    private RedisIdWorker redisIdWorker;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private RedissonClient redissonClient;
    @Autowired
    private IVoucherOrderService proxy;
    private static DefaultRedisScript<Long> SECKILL_SCRIPT;
    //使用静态代码块的目的：初始化静态代码块，只执行一次
    static {
        SECKILL_SCRIPT =new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }

    private static final ExecutorService SECKILL_ORDER_EXECUTOR= Executors.newSingleThreadExecutor();

    @PostConstruct
    private void init(){
        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
    }
    private class VoucherOrderHandler implements Runnable{
        String queueName = "stream.orders";
        @Override
        public void run() {
            while (true){
                try {
                    //1.获取消息队列中的订单信息 XGROUP GROUP g1 c1 COUNT 1 BLOCK 2000 STREAMS stream.orders >
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2)),
                            StreamOffset.create(queueName, ReadOffset.lastConsumed())
                    );
                    if(list == null || list.isEmpty()){
                        continue;
                    }
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> values = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);
                    //2.创建订单
                    handleVoucherOrder(voucherOrder);
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());
                } catch (Exception e) {
                    log.error("处理订单异常",e);
                    handlePendingList();
                }
            }
        }

        private void handlePendingList() {
            while (true){
                try {
                    //1.获取pendingList中的订单信息 XGROUP GROUP g1 c1 COUNT 1 BLOCK 2000 STREAMS stream.orders >
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1),
                            StreamOffset.create(queueName, ReadOffset.from("0"))
                    );
                    if(list == null || list.isEmpty()){
                        break;
                    }
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> values = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);
                    //2.创建订单
                    handleVoucherOrder(voucherOrder);
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());
                } catch (Exception e) {
                    log.error("处理pendingList订单异常",e);
                    try {
                        Thread.sleep(20);
                    } catch (InterruptedException ex) {
                        throw new RuntimeException(ex);
                    }
                }
            }
        }
    }
//    private final BlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<>(1024*1024);
//    private static final ExecutorService SECKILL_ORDER_EXECUTOR= Executors.newSingleThreadExecutor();
//
//    @PostConstruct
//    private void init(){
//        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
//    }
//    private class VoucherOrderHandler implements Runnable{
//        @Override
//        public void run() {
//            while (true){
//                try {
//                    //1.获取队列中的订单信息
//                    VoucherOrder voucherOrder = orderTasks.take();
//                    //2.创建订单
//                    handleVoucherOrder(voucherOrder);
//                } catch (InterruptedException e) {
//                    log.error("处理订单异常",e);
//                }
//            }
//        }
//    }

    private void handleVoucherOrder(VoucherOrder voucherOrder) {
        Long userId = voucherOrder.getUserId();
        RLock lock = redissonClient.getLock("lock:order:" + userId);
        boolean isLock = lock.tryLock();
        if (!isLock) {
            log.error("不允许重复下单");
            return;
        }
        //获取代理对象 (事务代理对象)
        try {
            proxy.createVoucherOrder(voucherOrder);
        } finally {
            lock.unlock();
        }
    }
    @Override
    public Result seckillVoucher(Long voucherId) {
        Long userId = UserHolder.getUser().getId();
        long orderId = redisIdWorker.nextId("order");
        // 1.执行lua脚本
        Long result = stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),//keys
                voucherId.toString(),//args
                userId.toString(),
                String.valueOf(orderId)
        );
        //2.判断结果是0
        int r=result.intValue();
        if(r!=0){
            //不为0 代表没有购买资格
            return Result.fail(r==1?"库存不足":"不能重复下单");
        }
        return Result.ok(orderId);
    }
//    @Override
//    public Result seckillVoucher(Long voucherId) {
//        Long userId = UserHolder.getUser().getId();
//        // 1.执行lua脚本
//        Long result = stringRedisTemplate.execute(
//                SECKILL_SCRIPT,
//                Collections.emptyList(),//keys
//                voucherId.toString(),//args
//                userId.toString()
//        );
//        //2.判断结果是0
//        int r=result.intValue();
//        if(r!=0){
//            //不为0 代表没有购买资格
//            return Result.fail(r==1?"库存不足":"不能重复下单");
//        }
//        //为0 代表购买资格 把下单信息保存到阻塞队列
//        VoucherOrder voucherOrder = new VoucherOrder();
//        long orderId = redisIdWorker.nextId("order");
//        voucherOrder.setId(orderId);
//        voucherOrder.setUserId(userId);
//        voucherOrder.setVoucherId(voucherId);
//        // 保存到阻塞队列
//        orderTasks.add(voucherOrder);
//        proxy = (IVoucherOrderService) AopContext.currentProxy();
//        return Result.ok(orderId);
//    }
//    @Override
//    public Result seckillVoucher(Long voucherId) {
//        //1.查询优惠券
//        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
//        //2.判断秒杀是否开始
//        if (voucher.getBeginTime().isAfter(LocalDateTime.now())) {
//            return Result.fail("秒杀尚未开始");
//        }
//        //3.判断秒杀是否结束
//        if (voucher.getEndTime().isBefore(LocalDateTime.now())) {
//            return Result.fail("秒杀已经结束");
//        }
//        //4.判断优惠券是否还有库存
//        if (voucher.getStock() < 1) {
//            return Result.fail("库存不足");
//        }
//        //5.实现一人一单逻辑
//        Long userId = UserHolder.getUser().getId();
//        // 创建锁对象
////        SimpleRedisLock lock = new SimpleRedisLock("order:" + userId, stringRedisTemplate);
//        RLock lock = redissonClient.getLock("lock:order:" + userId);
//        boolean isLock = lock.tryLock();
//        if (!isLock) {
//            return Result.fail("不允许重复下单");
//        }
//        //获取代理对象 (事务代理对象)
//        try {
//            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
//            return proxy.createVoucherOrder(voucherId);
//        } finally {
//            lock.unlock();
//        }
//
//    }

    @Transactional
    public void createVoucherOrder(VoucherOrder voucherOrder) {
        //一人一单
        Long userId = voucherOrder.getUserId();
        int count = query().eq("user_id", userId).eq("voucher_id", voucherOrder.getVoucherId()).count();
        if (count > 0) {
            log.error("用户已经购买过一次了");
            return ;
        }
        //5.扣减库存
        boolean success = seckillVoucherService.update()
                .setSql("stock=stock-1")// set stock=stock-1
                .eq("voucher_id", voucherOrder.getVoucherId())// where voucher_id=?
                .gt("stock", 0) // and stock>0
                .update();
        if (!success) {
            log.error("库存不足");
            return ;
        }
        save(voucherOrder);

    }
}
